This invention relates to firearms and deals more particularly with a unit for use in converting a blowback autoloading pistol into a gas operated one. It also deals with firearms, whether converted or of entirely new manufacture, using various features of the conversion unit, particularly a firearm having an improved bolt and bolt locking mechanism operated in response to the movement of a gas activated piston.
Heretofore many autoloading pistols have been of the blowback variety wherein during firing the blowback pressure exerted by the cartridge shell on the bolt is used to operate the bolt, during the course of which operation the bolt is unlocked for movement relative to the barrel, the spent shell ejected, a new cartridge brought to the firing chamber, the hammer cocked and the bolt returned to locked firing position. A very popular model of blowback autoloading pistol is the U.S. caliber .45 model 1911 pistol as made by Colt, Remington, Ithaca Gun Company and others with an estimated several million of such model pistols having been made from 1911 to date. Other autoloading pistols of generally similar design are the Browning Model P35, the Smith and Wesson Model 39, the Polish Radom and the Russian M1933 Tokarev. In all of these pistols the barrel and slide are separate parts with the barrel unlocking itself from the slide, which includes the bolt, as the slide moves to the rear in response to a firing. This design inherently causes a heavy recoil, inaccuracy because the barrel and sights are not integral and the need to change the recoil spring if loads of different operating pressures are used.
Despite the past popularity of blowback type autoloading pistols, a modern trend is toward gas operated pistols wherein a piston activated by the high pressure gases appearing in the barrel during firing operates a bolt to achieve the aforesaid functions of bolt unlocking, shell ejection, cartridge chambering, hammer cocking and bolt locking.
Since gas operated autoloading pistols are in demand a purpose of this invention is to provide such a firearm representing an improvement over those presently available or proposed. In this regard a more detailed object is to provide a smoothly operating and reliable bolt and bolt locking means for a firearm particularly well adapted for operation by a gas activated piston, which bolt and bolt locking means may be used with other types of gas piston activated firearms as well as with pistols.
Another object of the invention is to provide a conversion unit for converting an existing blowback autoloading pistol, such as U.S. .45 caliber model 1911, into a gas operated one. In keeping with this object a more detailed aim of the invention is to provide such a conversion unit which is very easily assembled with the receiver of the blowback pistol after its slide and barrel are removed.
Another object of this invention is to provide a conversion unit of the foregoing character allowing a conversion to be made without having to modify or alter, as by machining or otherwise, any part of the receiver frame or any parts carried by that frame.
A still further object of the invention is to provide a gas operated firearm either made as an entirely new article or made by converting a blowback pistol into a gas operated one through the use of a conversion unit such as described above, wherein an automatic control of the gas pressure applied to the piston is obtained thereby allowing the firearm to be used with cartridges of different load without having to change the recoil spring or make any other adjustment.
Other objects and advantages of the invention will be apparent from the following detailed description of a preferred embodiment of the invention taken in conjunction with the accompanying drawings.
In the drawings the illustrated conversion unit is one designed for connection to the receiver of a U.S. caliber .45 model 1911 autoloading pistol, however this has been done for convenience only and it should be understood that other conversion units generally similar to the one illustrated may be designed for use with other blowback pistols generally similar to the U.S. caliber .45 model 1911.